Understanding blood tests – a guide for people with lymphoma

Freephone helpline 0808 808 5555information@lymphomas.org.ukwww.lymphomas.org.ukUnderstanding blood tests– a guide for people withlymphomaWhen you are being tested or treated for lymphoma you will have to have blood samplestaken from time to time. You might wonder what the blood tests are all for and what theresults mean.This article aims to answer the most common questions people ask about blood tests:● Why are blood tests done when you have lymphoma?● What do blood tests measure?● Where do blood cells come from?● How does lymphoma affect the different blood cells – the white blood cells, platelets andred blood cells?● How long does it take for the blood cells to recover from the treatments?● Why do I need blood tests done before chemotherapy cycles?● What can I do if I find having blood tests frightening?There are some other, more specific questions about blood tests that callers to our helplineask from time to time and we have answered these too. Lastly, there will be some informationon the most common blood tests and what they mean and suggestions on where you can getmore information on blood tests.Why are blood tests done when you have lymphoma?Blood tests are done for various reasons, for example to:● help suggest the diagnosis when lymphoma is first suspected (this blood test evidence willthen lead the medical team to order other, more specific tests like a biopsy)● assess the lymphoma before treatment starts● check your general health before or during treatment● assess your progress or detect the development of complications during treatment● check whether you have recovered adequately from one cycle of treatment before startingthe next one● monitor the lymphoma during periods when you have not yet started treatment or afterthe treatment is finished.Blood testsLYM0022/BloodTests/2012v31/10

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The full blood countA full blood count (FBC for short) is done to look at the numbers of the different typesof blood cells in your blood. The machine in the laboratory also gives an indication of theaverage sizes of the cells and other useful information about them.In some cases a blood smear is prepared from the sample and is specially stained to look atthe cells directly under the microscope. This test gives the doctors more detailed informationon the blood cells, for example on whether they look normal in size and shape.Blood smear under the microscope showing red and white blood cells(Science Photo Library / C012/4499)The numbers of blood cells (the ‘counts’) and their appearance can help in the diagnosis ofsome lymphomas. There is some more information on the FBC in the table on page 9.Why do lymphoma treatments affect the blood counts?Treatments such as chemotherapy and radiotherapy are used to kill off lymphoma cells butunfortunately these treatments don’t distinguish between normal cells and abnormal cells.This means that the numbers of your normal bone marrow cells are often reduced bythe treatments. In addition, your bone marrow might not be working very well if there islymphoma in the marrow itself.This reduction in bone marrow cells means that fewer normal blood cells are manufactured.Fortunately, normal cells recover from the effects of the drugs faster than cancer cells, so theblood cells usually recover quite quickly and the counts go up again.What are the main types of blood cell that are assessed in the FBC?The main types of blood cells measured in the FBC are red blood cells, white blood cells andplatelets. Red blood cells are the most numerous of the different blood cells but we are goingto describe the white blood cells first. This is because they are the cells that are most affectedby lymphoma and by lymphoma treatments.Blood testsLYM0022/BloodTests/2012v33/10

White blood cells and lymphomaWhat do white blood cells do?There are several types of white blood cell, all of which are involved in different ways indefending the body against infection and in clearing up after infections. White blood cells arealso involved in our general immunity to infections, in inflammation and in allergic reactions.The numbers of white blood cells and their appearance in the FBC and in a blood smear canoccasionally help to detect a lymphoma and suggest what kind of lymphoma it is.Are white blood cells affected by lymphoma treatment?Yes, the white blood cell counts often fall. For people who are being treated for lymphoma theimportant white blood cells are the neutrophils. These only last in the bloodstream for a fewdays and they normally ingest (eat) and destroy bugs. This means that you can have problems withinfections if the bone marrow can’t produce them and you have fewer of them for a while.What does having a low neutrophil count mean to me?Having a low neutrophil count is called neutropenia. Getting an infection in this situation canbe very serious. Because you don’t have your normal defences, bugs that are normally harmlesscan overwhelm you. You might need intravenous antibiotics and other support to get over this,often in hospital.If you are unwell with a fever during your chemotherapy cycles you must therefore seek advicequickly. If you are also on steroids these can mask the fever, so if you feel distinctly unwell, evenwith a normal temperature, you should contact your medical team straightaway. You shouldhave been given telephone numbers from your treatment centre to call at any time of the dayor night in these circumstances – it is important to use them.Platelets and lymphomaWhat do platelets do?Platelets are small cell fragments that help your blood to clot. They plug any cuts or defects inthe blood vessels while the chemical clotting factors in your blood get to work to stabilise theplug. This plug then scars over and heals. The number of platelets measured in the FBC cansometimes be low in certain types of lymphoma that are present in the bone marrow. A lowlevel of platelets is called thrombocytopenia.Are platelets affected by lymphoma treatment?The production of platelets is affected by lymphoma treatments in just the same way as whiteblood cells are affected. Platelets last for longer in the bloodstream so platelet levels don’t tendto drop so far. It is therefore not so common to need treatment for low platelet counts whenyou are on lymphoma treatment, but this will depend on whether there is lymphoma in thebone marrow and on how intense the treatment is.How would I know if I have low platelets?A low platelet count won’t affect how you feel in yourself but can mean that you bruise orbleed easily, to a much greater extent than you would normally expect from minor injuries,Blood testsLYM0022/BloodTests/2012v34/10

for example. You might notice tiny areas of bleeding in the skin as little red spots on yourlower legs – this is known as purpura. If you are bruising or bleeding from a lack of plateletproduction, then a platelet transfusion (a bag of platelets from a donor) can be given totide you over. Rarely, low levels of platelets can happen for other reasons and alternativetreatments might be needed, rather than platelet transfusions (eg steroids).Red blood cells and lymphomaWhat do red blood cells do?Red blood cells are much more numerous in the blood than the other cells, which is whyblood is deep red in colour. The red cells contain a protein called haemoglobin, and oxygenthat has been breathed into the lungs attaches itself to this protein as the blood passesthrough the lungs. The job of red blood cells is therefore to carry oxygen around the body.If your red blood cell count is low or if the amount of haemoglobin in the red blood cells islow, this is called anaemia, which can make you feel tired and breathless. Some people withlymphoma will be anaemic when the lymphoma is first diagnosed.Are red blood cells affected by lymphoma treatment?Yes, but they are fairly long-lived cells (they last for months rather than days), so you canoften keep your oxygen-carrying capacity up reasonably well during chemotherapy. However,if you are anaemic to start with, have lymphoma in your bone marrow or have treatmentcomplications, a blood transfusion is sometimes necessary. If your chemotherapy is prolonged,the production of red blood cells in the bone marrow might be halted for so long thattransfusion becomes inevitable.How long does it take for blood cells to recover fromthe treatments?This varies between different chemotherapy regimens and between individuals. With thestandard outpatient chemotherapy regimens used for most lymphomas, the lowest point inthe cell counts (you might hear this referred to as the ‘nadir’) usually comes 7–14 days afterthe first day of the chemotherapy treatment cycle. After this low point the cell counts beginto rise. Because there is variation between people in how quickly this happens, however, yourblood counts will be checked before each cycle of treatment.Why do I need blood tests before chemotherapycycles?Generally, blood tests are done at this stage to check that the blood cells have recoveredfrom the last chemotherapy cycle, but they are also done to check that your liver and kidneyshave not been damaged. Occasionally the tests will be done to check that you don’t need atransfusion or to check that an infection has cleared up.Chemotherapy treatments are designed to be given at intervals, in ‘cycles’. The time betweenchemotherapy cycles is determined by the length of time it takes most people to recoverBlood testsLYM0022/BloodTests/2012v35/10

just enough from the previous cycleto cope with another one. This meansthat the tests need to be done asclose to the start of the next cycleas practically possible. On the otherhand, complex technology and expertinterpretation is involved in doingthese blood tests, so a certain amountof time is required to get the resultsback. It is a fine balancing act to timethe tests correctly.Sometimes a delay in starting the nextcycle is needed to allow furtherrecovery of your blood counts, or youmight need some treatment to boostthe counts. Most treatment protocolsand all clinical trials include detailedinstructions on what happens if the(Science Photo Library M530/0669)blood cell numbers are insufficientbefore treatment. Very occasionally, treatment protocols proceed ‘metronomically’, meaningthat the next cycle of treatment starts on time, whatever the blood tests show.What can I do if I find having blood tests frightening?You are not alone. Nobody is keen on having blood tests, especially when frequent samples areneeded or if it is difficult to get blood from your veins. If you have to have a lot of tests doneyou tend to get more and more used to the process but it can still be hard. Some people havefound that it helps to have someone with them, such as a family member or a friend, to chat towhile the sample is being taken.There is a lot that can be done to ease the situation if you have always had a problem withblood tests. Firstly, it is important to explain how you feel to the nurses and phlebotomists(people specially trained to take blood). There are generally two distinct types of problem,though some people suffer from both. Firstly, if you tend to ‘come over peculiar’ or feel faint,then you should be lying down in a reasonably cool room to have blood taken. If the needlestingis part of the problem, ask for some anaesthetic cream to put on beforehand (such asEMLA cream). Another important thing to do is to look away during the procedure until it iscompletely finished.The second type of problem is a much more deep-seated ‘needle phobia’, which is a recognisedmedical condition in which people experience intense anxiety before blood is taken or beforeother procedures involving needles. This often goes back to having a bad experience as a child.The tips described in the last paragraph often help but it is well worth also considering taking asedative tablet beforehand and listening to some relaxation music during the procedure. If thereis enough time you could be referred to a psychologist for help. In the interests of time, thiskind of help would usually take the form of a ‘fast phobia cure’ rather than a more prolongedpsychoanalytical process.Blood testsLYM0022/BloodTests/2012v36/10

You should also ask your nurse to anticipate how much trouble taking repeated blood sampleswill be for you and for them. This will depend on the particular treatments you will be given andon how easy or difficult they think it will be to take blood from your veins. If they think that takingrepeated blood tests from you could be difficult, ask about having a central line inserted (such as aHickman ® line). As well as being used for giving you chemotherapy and other treatments directlyinto your veins, it might be possible to take blood tests through the line.Other common questions people ask about blood testsHow can my blood tests be normal if I have lymphoma?To affect the blood tests the lymphoma has to exert some influence on the bone marrow or theorgans or have particular features which show up in some tests. If the lymphoma is just confinedto the lymph nodes (glands) it might not affect any of the blood tests. Another reason for normaltests is that you are in remission.Why do some people have more tests than others?If someone appears to be having more tests than you this could be because:● the treatment for their lymphoma needs to be more intense than yours● they have had some complications previously● they have lymphoma in the bone marrow● they have other medical conditions that need extra monitoring, such as diabetes.How do the doctors and nurses decide which tests to do?Which tests are needed and when they are needed is determined by:● any symptoms you are having that the doctors want to investigate● the type of lymphoma you have● the type and intensity of the treatment you are having● the blood cell counts you need to achieve before proceeding to the next cycle● the treatment protocol or clinical trial you are on● the complications that can be associated with the particular drugs you are taking● your previous blood results.Can I see my results?You can, of course, ask to see these. Your nurses will often discuss the results in detail with you.Please ask your doctor or nurse if you are worried about a particular result – it might not meanwhat you think it does and you can worry needlessly about results that are not concerning to themedical team.Can tests be taken through my central line?Generally yes, blood samples can be take through a Hickman ® line or PICC (peripherally insertedcentral catheter). However, even a line working very well can fail to give out samples despite thedoctors’ or nurses’ best efforts – usually due to the position of the line at the other end.Blood testsLYM0022/BloodTests/2012v37/10

Why do tests sometimes have to be repeated?It is quite common for blood tests to be repeated. Here (in no particular order) are thecommonest reasons why this might happen:● It is rare for there to be a problem with the sample or bottle itself or for a technical hitch inthe laboratory – but it can happen, and then the test would need to be repeated.●● Occasionally a test result is unexpectedly very abnormal so the laboratory will suggestrepeating it soon – if the abnormality is confirmed, action can be taken to correct it if needed. Samples for ‘cross-matching’ blood for transfusion sometimes need to be repeated nearer tothe time of the transfusion to confirm the blood type shown in the previous test. The rulesabout this tend to get stricter the more transfusions you have, as you are more likely to havedeveloped an antibody and so risk having an immune reaction against the next transfusion.● If your pre-chemotherapy tests are close to the desired levels (but not quite good enough)and the laboratory feels that they are likely to be satisfactory by the day of your next cycle,they might ask for the tests to be repeated just before you proceed with the next treatment.● Tests for detecting infection or your body’s response to infection might need to be repeatedto see if it has cleared up.I have far fewer tests now I’m being followed up – why?It is only when you are having treatment that you will experience the more sudden and/orshort-lived changes in your blood tests, such as the blood cell counts dropping. In addition, thecomplications of treatments are much more likely to happen while you are still on the drugs.This is why you are closely monitored by blood tests while you are on treatment but don’t needso many afterwards.If particular blood tests, such as the lactate dehydrogenase (LDH) or the erythrocytesedimentation rate or ‘ESR’ (see the table on page 9), were found to be raised because of yourlymphoma, then repeating these tests can be helpful when you are being followed up. How oftenthey should be done is open to debate – most tests generally tend to be less useful later onduring the follow-up stage than they are while you are actually having symptoms of the illness.Why do you need blood tests if you take warfarin?A few people develop a clot in the veins (for example in the lung) during their lymphomatreatment and this is usually treated with injections of an anticoagulant (anti-clotting) drug calledheparin. If you need treatment with heparin you might be switched later to warfarin tabletsto thin the blood. You will be given quite a bit of information about this treatment. Becausedifferent people respond to these tablets differently, each person will need a slightly differentdose of warfarin to achieve the same degree of blood thinning.The laboratory staff and doctors judge the correct dose of warfarin to give you by doing regularblood tests (the main one is called the INR, which is short for ‘international normalised ratio’).If there are changes in your health (for example if you are put on antibiotics) the warfarin dosewill often need to be changed. This means that you will need extra monitoring tests done inorder to adjust the dose accurately. Unfortunately, there is no substitute for having regular testsuntil you come off warfarin.Blood testsLYM0022/BloodTests/2012v38/10

Some common tests explainedFBCESRA ‘full blood count’ is a test that measures the numbers of red blood cells,white blood cells and platelets in your blood. There is not an exact numberof cells that is regarded as being ‘normal’ – there is a range of numbers that isregarded as normal and this range varies slightly between laboratories.The range also differs between men and women and in children.This stands for ‘erythrocyte sedimentation rate’ and it is a test that measuresthe thickness of the blood. Some laboratories do a similar test called the‘plasma viscosity’. Both tests measure the same thing and give the sameinformation. The ESR is commonly raised if lymphoma is present. Because theESR can be raised if lymphoma becomes active, keeping an eye on your ESR isone way of checking that the lymphoma has not relapsed (come back).A word of warning: the ESR is not useful for assessing lymphoma activity ineveryone with a lymphoma, and it can be raised or abnormal in many othermedical conditions (eg in infections) so it needs to be interpreted carefully.CRPLDHThis stands for ‘C-reactive protein’ and this is another general test. It is notgenerally used for monitoring the lymphoma itself but can be very useful tomonitor you if you have a serious infection (it is high to start with and dropsif the antibiotics are working).This stands for ‘lactate dehydrogenase’, which is a substance in the bloodwhich is at higher than normal levels in some types of lymphoma. Raised LDHlevels in the bloodstream might indicate that a lymphoma is growing, but(as with the ESR) a high LDH level can be present as a result of other medicalconditions as well.AcknowledgementThe Lymphoma Association is grateful to Dr Paul Revell, consultant haematologist at StaffordHospital, for writing this article in 2009 and for updating this new version.Useful sources of further information on blood testsNHS Choiceshttp://www.nhs.uk/conditions/Blood-tests/Pages/Introduction.aspxCancerHelp UK (Cancer Research UK) 0808 800 4040 (Monday–Friday, 9am–5pm) via websitehttp://www.cancerhelp.cancerresearchuk.orgBlood testsLYM0022/BloodTests/2012v39/10

ReferencesHoffbrand AV, Moss PAH. Essential Haematology. 6th edition. 2011. Wiley-Blackwell, Oxford.Deacon B, Abramowitz J. Fear of needles and vasovagal reactions among phlebotomy patients.Journal of Anxiety Disorders, 2006. 20: 946–960.Fernandes PP. Rapid desensitization for needle phobia. Psychosomatics, 2003. 44: 253–254.Hamilton JG. Needle phobia: a neglected diagnosis. The Journal of Family Practice, 1995.41: 169–175.How we can help youWe provide:● a free helpline providing information and emotional support 0808 808 5555 (9am–6pmMondays–Thursdays; 9am–5pm Fridays) or information@lymphomas.org.uk● free information sheets and booklets about lymphoma● a website with forums and a chatroom – www.lymphomas.org.uk● the opportunity to be put in touch with others affected by lymphoma through our buddy scheme● a nationwide network of lymphoma support groups.How you can help usWe continually strive to improve our information resources for people affected bylymphoma and we would be interested in any feedback you might have on this article. Pleasevisit www.lymphomas.org.uk/feedback or email publications@lymphomas.org.ukif you have any comments. Alternatively please phone our helpline on 0808 808 5555.We make every effort to ensure that the information we provide is accurate but it shouldnot be relied upon to reflect the current state of medical research, which is constantlychanging. If you are concerned about your health, you should consult your doctor.The Lymphoma Association cannot accept liability for any loss or damage resulting fromany inaccuracy in this information or third party information such as information onwebsites which we link to. Please see our website(www.lymphomas.org.uk) for more information abouthow we produce our information.© Lymphoma AssociationPO Box 386, Aylesbury, Bucks, HP20 2GARegistered charity no. 1068395Produced 25.04.2012Next revision due 2014Blood testsLYM0022/BloodTests/2012v310/10